This invention relates to a thickener-rheology modifier system for personal care compositions and particularly for hair and skin care compositions comprising the combination of a hydrophobically modified alkali-soluble thickener and a polysaccharide hydrocolloid or gum-type thickener or polyalkylene glycol, preferably with a surfactant and more preferably with boric acid.
Polymeric water-soluble thickening agents are widely known and used in many aqueous systems including coating applications, household and personal care products. Carboxyl-containing copolymers produced by the addition or free-radical polymerization of ethylenically unsaturated monomers and that swell or solubilize to thicken aqueous media on neutralization are commonly referred to as alkali-swellable or alkali-soluble thickeners. Hydrophobically modified or associative alkali-soluble thickeners have been developed to provide enhanced thickening properties. A description of alkali-soluble thickeners (AST) and associative AST's can be found in an American Chemical Society article by G. D. Shay entitled “Alkali-Swellable and Alkali-Soluble Thickener Technology”, 1989, pp. 457–493.
While different thickeners including associative alkali-soluble thickeners have been disclosed in various applications, there still is the desire to find a system which provides suitable thickening as well as other rheological properties needed for personal care applications. This invention provides a thickener-rheology modifier system which significantly improves the thickening properties of alkali-swellable thickeners and also improves rheology characteristics of gel textures and emulsions from brittle/cuttable to more flowable, shear thinning and makes the products aesthetically acceptable for personal care use.